Process for dyeing nylon to produce multi-colored dyeings



United States Patent Bfllhfififi Patented Jan. El, 1954 "iceSpartanhurg, S.C. No Drawing. Filed Feb. 8, 1961, Ser. No. 87,786Claims. (Cl. 8-14) This invention relates to a novel method of dyeingnylon, more particularly to a method of dyeing nylon to producemuiti-colored effects in a single dye bath, and to the nylon thus dyed.

According to this invention, multifilament nylon 1s dyed at an acid pHin a dye bath comprising at least one dyestulf and an aryl sulfonic acidcondensation product, all as defined hereinafter, to produce amulti-colored dyeing thereof.

In British patent specification 680,862, there is disclosed and claimedby me a method of dyeing normal wool employing dyestuffs containing atleast 2 sulforuc acid groups and certain aryl sulfonic acid condensationproducts to produce multi-colored dyeings in a single dye bath withoutresorting to mixtures of wools having different dyestuff affinities.This process takes advantage of ditferences in dyestuff affinity ofvarious sites along the wool fibers, which differences are not observedin the usual dyeings. The process is believed to depend upon theheterogenous'nature of normal wool due to either the variety of aminogroups making up its chemical structure or its nonuniform physicalstructure, or both.

Thus, it was believed that an analogous process would not be possiblewith synthetic fibers because of their uniform physical and chemicalstructure. This belief was found to be substantiated with, for example,the polyesters and the acrylics. However, it was found that withmultifillament nylon an effect similar to that observed with wool couldbe produced. This was most surprising because there was nothing aboutthe chemical or physical nature of nylon which would suggest thatdifferent dyestulf afiinities existed along the filament length. Thiseffect is not due to the presence of mixtures of different types ofnylon in the dye bath, e.g., a mixture of nylon 66 and nylon 6, althoughthe difference in dyestu'lf atfinities between these two types of nylonscan be markedly enhanced by the process of this invention to the extentthat a reserve of nylon 66 can be achieved, if desired. 0n the contrary,nylon multifilament yarns that were believed to be substantially uniformin physical and chemical structure have sufficiently different dyeingcharacteristics along the filament length to enable the production ofmulti-colored elfects in a single dye bath when following the process ofthis invention.

It is an object of this invention to provide a process for obtainingmulti-colored dyeing effects on multifilament nylon in a single dye bathwithout resorting to mixtures of different types of nylon.

it is another object of this invention to provide a process for dyeingnylon fabrics and piece goods to give multi-colored effects.

It is another object of this invention dyed multifilament nylon yarn,woven and ties, garments, and other piece goods.

Other objects will be apparent to those skilled in the art to which thisinvention pertains.

The term multi-colored when used herein means a mixture of any two ormore colors, including white. Thus, nylon dyed a mixture of red andwhite or two shades of red is multi-colored according to thisdefinition.

It is to be understood that the mulLi-colored dyeings obtained accordingto this process are those obtained as a result of non-solid dyeingsalong the length of filaments of one type of nylon. However, thisefifect can be to provide novel knitted fabachieved concomitantly withthe contrast dyeings that are obtained when dyeing two types of nylon,e.g., nylon 6 plus nylon 66.

Nylon which can be dyed according to this process are multi-filamentnylon yarns and woven and knitted nylon garments prepared therefrom,e.g., socks, sweaters, sport shirts and blouses and fabrics and otheryard goods, e.g., upholstery and carpet materials. While this inventionis primarily directed to multi-filament nylon, i.e., continuous lengthsof nylon, it will be apparent to those skilled in the art that anobvious equivalent thereto is nylon in which the length of nylon is cutinto staple length and spun before being formed into yarn.

The preferred type of nylon to be used in the process is nylon 6, due toits greater dyestuff afiinity. Especially preferred is bright nylon,i.e., nylon which has little or no pigments or fillers added thereto.The preferred multi-filament nylon yarn has a. total denier of at leastand a denier per filament of between about 2 and 10. An example of suchyarns are carpet yarns having a total denier of at least 1,000 and adenier per filament of about 10 or less, usually 4,000 or more totaldenier and about 7 or less per filament. Very pronounced multicoloreddyeings are somewhat more difficult to achieve with texturized nylon,particularly if the tenacity of the yarn is increased to a high levelduring the texturizing process. This dificulty is less pronounced whenthe texturized nylon is dyed in the form of knitted fabrics, piecegoods, or garments. Low or medium tenacity nylon, i.e., having atenacity of less than about 7 grams per denier, is preferred and shouldordinarily be employed in the process of this invention.

The dyestuifs which are employed in the process of this invention arethose which dye nylon and which contain at least 2 sulfonic acid groups,preferably 3 or more, and from 0 to 3 reactive groups in the molecule,the sum of the sulfonic groups and reactive groups being at least 3. Thedyestuffs containing reactive groups, e.g., vinyl sulfone or cyanuricchloride groups, are referenced to in the dyeing art as reactivedyestuffs. Included in the dyestuifs containing 3 or more sulfonic acidand reactive groups are the acid dyestuffs, milling dyestuffs, di rectdyestuffs and cotton dyestuffs. These dyestuffs are ordinarily suppliedby the manufacturer in the form of sodium salts. The term sulfonic acidgroup excludes those groups in which the sulfonic acid group is in theform of an inner salt with a basic group. The preferred dyestuffs forthe process of this invention are those in which the number of sulfonicacid groups therein is 3 or more.

The dye baths of this invention are acid, i.e., they contain an organicor inorganic acid, or acidic salt, e.g., acetic acid, formic acid,sulfuric acid, lactic acid, citric acid or other aliphatic acid, orphosphoric acid, or acidic salts thereof, e.g., the ammonium salts. Itis preferred that the starting pH of the dye bath be between about 2 and5. If desired, the pH can be varied during the dyeing by employingammonium sulfate or phosphate and then permit the pH to drift lowerduring the dyeing. The amount of acid to be employed will depend uponthe affinity of the dyestuff employed in the dyeing to nylon in thepresence of the condensation products as defined hereinafter. As thecondensation products employed in the process of this invention areretarding agents for dyeing nylon, it is sometimes necessary to usesomewhat greater amounts of acid or a stronger acid than would normallybe employed with these dyestuffs. One percent to five percent aceticacid or 1% to 5%, usually 1% to 3% of formic, sulfuric, or pho phoricacid, calculated on the weight of the nylon, is the usual range.

The condensation products employed in the process of this invention aregenerally known as retarding or leveling agents, usually for dyeingwool. They are characterized chemically as condensation products ofaryl, usually carbocyclie, sulfonic acids and an aldone. The term aldoneas used herein means an aldehydic or ketonic carbonyl compound, e.g.,formaldehyde, acetaldehyde, benzaldehyde, benzoin, acetone, etc. Theseare a well known and commonly employed class of compounds in the dyeingart. They each possess at least two sulfonic acid substituted arylgroups in the molecule. Compounds within this definition are mono, di,or trisulfonic acid substituted benzene or naphthalenes which canfurther be substituted with lower-alkyl, hydroxy, nitro, amino, etc.,groups and which have been condensed with an aldone as described aboveto produce a dimer, trimer or polymer linked by the aldone by a reactionwell known in the art. Compounds such as dihydroxy-phenyl sulfone canalso be incorporated in the condensation reaction to produce a mixedcondensation product. See US. 2,623,806. These compounds include thecondensation products of naphthalene-1 or naphthalene-2 sulfonic acid,or naphthalene-2,7-

disnlfonic acid and formaldehyde, e.g., those of the formula Ho s):

not

and the alkali-metal salts thereof when n is 0, 1, 2 or more, usually or1, and x is 1 or 2. Others include the condensation product of phenol orcresol sulfonic acid and formaldehyde, e.g., of the formula on on (1)11(SOaIEDx /X 1 Jim.

I R I 80313: SOaH and the corresponding alkali-metal salts thereofwherein R is H or CH and n is 0 to 3 or 4. Still others include thecondensation products of phenol, cresol, or naphthalenesulfonic acid andbenzoin or acetone and their alkalimetal salts.

Specific examples of such condensation products aredinaphthylmethanedisulfonic acid, diphenylmethanedisulfonic acid,dihydroxyphenylmethanedisulfonic acid, dicresylmethanedisulfonic acid.dihydroxynaphthylmethanedisulfonic acid,dinitronaphthylmethanedisulfonic acid, dichloronaphthylmethanedisulfonicacid, diaininonaphthylmethanedisulfonic acid,dinaphthylmethane-2,7,2',7'tetrasulfonic acid and the sodium salts ofeach.

The amount of aryl sulfonic acid condensation product employed is anamount, between 0.1 and 5% calculated on the weight of the nyloninsuflicient to reserve the dyestulf employed. Usually an amountsuflicient to noticeably reduce the dyeing rate of the effect dyestutfis employed, i.e., so that the condensation product acts as a retardingagent. Between about 0.25% and 3% is the usual range.

In carrying out the process of this invention, the selectedmulti-filament nylon, usually in the form of yarn or fabrics or piecegoods woven or knitted therefrom, is dyed at an acid pH in a dye bathcontaining a dyestuff which will dye nylon and the selected arylsulfonic acid condensation product as defined hereinbefore. The usualdyeing techniques are employed, i.e., the nylon is usually added to thecold dye bath and the temperature then raised to the boil, with thedyeing continued until exhaustion or equilibrium is achieved. Ifdesired, the nylon can be contacted with the aryl sulfonic acidcondensation product before the dyestuif. However, for convenience andsimplicity sake, the two ingredients are usually incorporated togetherin the dye bath.

0 The nylon was washed, dried The effects obtained will, when using asingle dyestuff,

6" of a formaldehyde naphthalenesulfonic vary from a tone on tone to acolor on white, each of the above effects being within the termmulti-colored as used herein. Spectacular effects are obtained if thedye bath additionally contains at least one of a dyestuff containingless than two sulfonic acid groups and a dyestutf which contains atleast one more sulfonic acid group and preferably two more sulfonic acidgroups, as compared with the dyestuffs as described hereinbefore. Withsuch a mixture of dyestuffs, a rainbow of colors can be achieved from asingle dye bath.

The effects produced by this invention, particularly when a mixture ofdyestuifs as described above is employed, are frequently enhanced if thematerial to be dyed is knitted fabric or garments or material such asupholstery fabrics or tufted carpeting. The deposition of the variousdyestuffs appears to be influenced by the type of construction of thematerial being dyed. Thus, it has been found that when employing adyestuif having three sulfonic acid groups along with an all over color,i.e., a dyestuff having less than two sulfonic acid groups, the highersulfonic acid dyestuff appears to concentrate itself at the base of thetufts where accessibility is more diffi- (SOsH);

cult, although the converse of this would be expected. Because of thisphenomena, completely new effects can be obtained where dyeing piece andflat goods such as knitted fabric and garments and carpets.

When equilibirium or exhaustion has been achieved, the nylon can then bewashed and dried in the usual fashion. The usual dyestulf additives,e.g., Glaubers salt or other materials used as leveling agents ornonionic wetting agents, may be added to the dye bath to facilitate theprocess. However, as with other dyeings, such additives may altersomewhat the result obtained. Usually, it is preferred to keep theseother additives to a minimum.

It has been found that the effect obtained can be altered somewhat bypretreatment of the nylon with formaldehyde or paraformaldehyde, e.g.,by heating or boiling the nylon for a short time in an aqueous solutioncontaining up to about 2% formaldehyde or paraformaldehyde, calculatedon the weight of the nylon. The nylon can then be washed and dried inthe manner described herein. Alternatively, the formaldehyde can beincorporated in the dye bath.

Similarly, the results can be somewhat modified by treating the nylonwith acid prior to the addition of the condensation product and dyestuffor contacted with the condensation product prior to the acid anddyestuif. By these modifications, a wide variety of effects and shadescan be obtained, thus enhancing the versatility of the process.

The following examples are illustrative of the process of this inventionbut are not to be construed as limiting. All percents are based upon theweight of the nylon being dyed.

Example I Five thousand denier 816 filament, 1 /2 8 twist Caprolan brandbright, medium tenacity, multi-filament nylon yarn was dyed in a dyebath containing 2% acetic acid, 0.5 acid condensation product (ErionalNW) and 0.5 of Fastusol Blue LFFR, a cotton dyestuif containing not lessthan 3 sulfonic acid groups. The dye bath was brought to a boil in about20 minutes and boiling was continued for about one hour. and found to bedyed a mixture of blue and white, similar to a stock dyeing.

Example 11 The procedure of Example I was followed exactly except that0.5% of Acilan Crocein F913 (Acid Red 47, Cl.

27300), a 4 sulfonic acid dyestufi, was substituted for the dyestuff. Apeppermint stick red and white was obtained.

Example 111 The procedure of Example I was followed exactly except thatPyrazol Fast Red 6 BL (Direct Red 79, CI. 29065), a 4 sulfonic aciddyestulf, was substituted as the dyestuff. The nylon was dyed a mixtureof white and moderately dark red.

Example IV The procedure of Example I was followed exactly ex cept that0.5% Fastusol Scarlet LGG (Direct Red 76, CI. 40270), a 3 sulfonic aciddyestuif, was substituted as the dyestufi. The nylon was dyed a lightmixture of white and orange.

Example V The procedure of Example I was followed exactly except that0.5 of Solantine Gray BL (Direct Black 74, CI. 34180), a sulfonic aciddyestuff, was substituted as the dyestuff. The nylon was dyed a mixtureof pastel blue and white.

Example VI The procedure of Example I was followed exactly except that0.5% Cibacron Black BG, a reactive dyestulf containing more than 2sulfonic acid groups, was substituted as the dyestufi. The nylon wasdyed a mixture of blue-gray and white.

Example VII Five thousand denier, 816 filament, 1 /2 8 twist brightnylon yarn was dyed in a dyebath containing 0.5 Solar Yellow 3LG, acotton dyestufi containing not less than 4 sulfonic acid groups, 0.1%Procion Blue I-IBS, a reactive dyestutf containing more than 2 sulfonicacid groups, 0.1% Calcoid Eosine G (Acid Red 4, Cl. 14710), a 1 sulfonicacid dyestuff, 3% acetic acid and 0.5% of a formaldehydenaphthalenesulfonic acid condensation product (Erional NN). The dye bathwas brought to the boil with occasional stirring in about 30 minutes andthen boiled for about an hour. The nylon yarn was washed and dried andfound to be dyed a pink mingled with shades of blue-gray.

Example VIII The procedure of Example VII was followed, except that 0.1%rocion Brilliant Red H338, a reactive dyestuff containing more than 2sulfonic acid groups, 0.15% of Milling Yellow 5G, a 1 sulfonic acidyellow dyestulf, and 0.12% of Alpharazine PG (Acid Blue 9, CI. 42090), a2 sulfonic acid dyestuif, were employed as the dyestuffs. A pastelmulti-colored dyeing was obtained containing pinks, lavenders, blues,greens, oranges and yellows.

xamples IXXIV Examples iVI were repeated except that the nylon andacetic acid were stirred together at room temperature for a few minutesin the dye bath before the formaldehyde naphthalene sulfonic acidcondensation product and dyestuff were added to the dye oath.Substantially the same effects were produced.

Example XV A mens stocking knit from spun nylon 6 staple was dyed in adye bath containing 5% acetic acid, 0.5 of a formaldehydenaphthalenesulfonic acid condensation product (Irgasol DA), 0.15% SolwayUltra Blue B 150% (Acid Blue 78, O1. 62105), a one sulfonic aciddyestuif, 0.12% Polar Brilliant Red G, a two sulfonic acid dyestulf and0.3% Cibacron Yellow G, a reactive dyestuif containing at least 3sulfonic acid groups, the dye bath was brought to the boil andmaintained at the boil for at least one-half hour. The resulting dyeingwas a threetone blue and green lovat type shade containing a little red.

6 Example XVI Two hundred seventy g. of tufted multi-level carpet madefrom Du Pont 501 textured semi-dull nylon 6 was scoured with a nonionicdetergent (Tergitol NPX), rinsed and then dyed in a miniature stripoverhead Beck Dyeing Kettle with a liquor ratio of about 40:1. While thefabric circulated, 3% of orthophosphoric acid was added to the cold bathwhich was then warmed to F. After 5 minutes, 1% of paraformaldehyde wasadded followed by 1% of a formaldehyde naphthalenesulfonic acidcondensation product (Erional NW) and then by a mixture of 0.2%Neopilate Brown GR, a premetallized dyestuff containing 0-1 sulfonicacid groups, 0.2% of Solophenyl Yellow AUF, a cotton dyestuif containing3 or more sulfonic acid groups and 0.05% of Cibacron Orange 2E, areactive dyestufi containing at least 2 sulfonic acid groups. The carpetstrip was circulated in the dye bath while the temperature thereof wasbrought to the boil. Boiling continued for one hour. The dyed effect wasa mixture of gold and light brown.

Example XVII The procedure of Example XVI was followed exactly exceptthat the paraformaldehyde was eliminated. The effect obtained wassimilar but somewhat softer. Similarly, the ortho-phosphoric acid can besubstituted by acetic acid.

Example XVII The procedure of Example XVI was followed exactly employing0.2% of Xylene Light Yellow 26?, a 1 sulfonic acid dyestuff, 0.4% ofCibacron Brilliant Orange G, a reactive dyestuif containing at least 2sulfonic acid groups, 0.2% of Pontamine BT, a cotton dyestuff containingat least 3 sulfonic acid groups, as the dyestuffs. The carpet was dyed2-tone burnt orange.

Example XIX The carpet described in Example XVI was dyed in the samemanner employing 5% acetic acid, 1% of formaldehydenaphthalene-sulphonic acid condensation product (Erional NW), 0.25% ofAnthraquinone Blue SWF (Acid Blue 25, CI. 62055), a 1 sulfonic aciddyestuflf, 0.12% Polar Brilliant Red G (Acid Red 122), a 2 sulfonic acidmilling dyestuff, and 0.3% of Pyrazol Red 7BSW (Direct Red 80, Cl.35780), a 6 sulfonic acid cotton dyestuff. The carpet was dyed a mixtureof red, blue and purple.

Example XX Nylon fabric woven from 5,000 denier, 816 filament, 1 /2 5twist Capralan bright nylon 6 was added to a warm dye oath containing 3%acetic acid, 0.5 of a condensation product of aryl aromatic sulfonicacid and benzoin (Albetex W.S.). The dyebath was brought to a boil andboiling was continued for about 15 minutes. The fabric was dyed amixture of copper and gold.

What is claimed is:

1. A process for dyeing multifilament and spun staple nylon yarns andfabrics, garments and piece goods formed therefrom to producemulti-colored dyeings in a single dyebath which comprises dyeing saidnylon in a dyebath containing a dyestulf containing at least 2 sulfonicacid groups and from 0-3 reactive groups in the molecule, the sum of thesulfonic acid groups and reactive groups being at least 3, at an acidpH, in the presence of a Water soluble condensation product of an arylsulfonic acid and an aldone in an amount, between 0.1% and 5% calculatedon the weight of the nylon, insufiicient to reserve said dyestuif,thereby producing multicolored dyed nylon without the necessity of anyspecial treatment of the nylon.

2. The process of claim 1 wherein the condensation product is that of anaryl sulfonic acid and formaldehyde.

3. The process of claim 1 wherein the condensation product is that of anaryl sulfonic acid and benzoin.

4. The process of claim 1 wherein the nylon has a tenacity of less thanabout 7 grams per denier, the dyebath additionally contains a dyestuifcontaining less than a total of 2 sulfonic acid groups and reactivegroups in the molecule.

5; A process for dyeing multifilarnent nylon having a tenacity of lessthan about 7 grams per denier to produce multi-colored dyeings in asingle dyebath which comprises dyeing said nylon in a dyebath containinga dyestuff containing at least 3 sulfonic acid groups in the molecule,an acid and a water soluble condensation product of an aryl sulfonicacid and an aldone in an amount, between 0.1% and 5% calculated on theweight of the nylon, insufiicient to reserve said dyestuff, therebyproducing multicolored dyed nylon Without the necessity of any specialtreatment of the nylon.

6. The process of claim 5 wherein the condensation product is that of anaryl sulfonic acid and formaldehyde.

7. The process of claim 5 wherein the condensation product is that of anaryl sulfonic acid and benzoin.

8. The process of claim 5 wherein the nylon is type 6 bright nylon.

9. A process for dyeing yarns, garments and flat goods prepared frommultifilament type 6 nylon multifilament nylon of a total denier of atleast 100 and a denier per filament of between about 2 and 10 and atenacity of acid and an aldone in an amount, between 0.1% and 5calculated on the weight of the nylon, sufficient to retard butinsutficient to reserve said dyestufi containing at least 3 sulfonicacid groups in the molecule, thereby producing multicolored dyed nylonwithout the necessity of any special treatment of the nylon.

10. The process of claim 9 wherein the nylon is sernidull nylon in theform of tufted carpet.

References Cited in the file of this patent UNITED STATES PATENTS2,199,233 Williams Apr. 30, 1940 2,289,232 Babcock July 7, 19422,480,775 Ryan Aug. 30, 1949 2,900,218 Gray Aug. 18, 1954 FOREIGNPATENTS 680,862 Great Britain Oct. 15, 1952 218,920 Australia Dec. 3,1958

1. A PROCESS FOR DYEING MULTIFILAMENT AND SPUN STAPLE NYLON YARNS ANDFABRICS, GARMENTS AND PIECE GOODS FORMED THEREFROM TO PRODUCEMULTI-COLORED DYEINGS IN A SINGLE DYEBATH WHICH COMPRISES DYEING SAIDNYLON IN A DYEBATH CONTAINING A DYESTUFF CONTAINING AT LEAST 2 SULFONICACID GROUPS AND FROM 0-3 REACTIVE GROUPS IN THE MOLECULE, THE SUM OF THESULFONIC ACID GROUPS AND REACTIVE GROUPS BEING AT LEAST 3, AT AN ACIDPH, IN THE PRESENCE OF A WATER SOLUBLE CONDENSATION PRODUCT OF AN ARYLSULFONIC ACID AND AN ALDONE IN AN AMOUNT, BETWEEN 0.1% AND 5% CALCULATEDON THE WEIGHT OF THE NYLON, INSUFFICIENT TO RESERVE SAID DYESTUFF,THEREBY PRODUCING MULITCOLORED DYED NYLON WITHOUT THE NECESSITY OF ANYSPECIAL TREATMENT OF THE NYLON.